Genetic and molecular analysis of virulence in the Hessian fly to resistance in wheat.

摘要

Virulence of Hessian fly, Mayetiola destructor (Say) to resistance gene H13, which was recently deployed in the soft red winter wheat cultivar “IN 9811” was studied to determine if this interaction operates on a gene-for-gene basis. Results revealed that a single, recessive sex-linked gene controls virulence in the insect and supported gene-for-gene specificity in the interaction. Additionally, genetic analyses of virulent/avirulent phenotypes confirmed previous observations that males express only maternally derived sex chromosomes in the soma. Segregation of white and dark eye color in H13 virulent backcross individuals showed a significant (P 0.001) deviation from the expected 1:1 phenotypic ratio, which indicated that the locus controlling the white-eye trait (w) was linked to the locus controlling virulence to H13 (vrH13). Recombination frequency between the locus controlling eye color and that controlling virulence was about 24.3 ± 2%. A sequence tagged site (STSE9 ₆₁₇) linked to the locus controlling virulence in Hessian fly to resistance gene H13 in wheat (vrH13) and the locus controlling white-eye (w) was identified. In situ hybridization to salivary polytene chromosomes of this sequence tagged site (STSE9₆₁₇) revealed that w, STSE₆₁₇, and vrH13 loci are on sex chromosome X1. The results of this work have contributed to the integration of the gene controlling virulence to H13 into a developing genetic and cytogenetic map as well as the feasibility of map-based positional cloning of the gene.